Model of the arc earth-fault for medium voltage networks

Marciniak, Lubomir

doi:10.2478/s13531-011-0020-y

Cited by 15 publications

(13 citation statements)

References 5 publications

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“…After assuming that values of certain parameters amounted to zero it was possible to obtain special cases of approximation frequently applied in computational practice. Because of the fact that in some computational models the above-named characteristics are used in the modelling of AC arc, sometimes it is worth taking into consideration a specific value of ignition voltage, resulting from physical processes occurring in the plasma column during momentary current decay [11][12][13]. The moderation of the passage of the voltage diagram across the origin of coordinates (i, u) can also be obtained through the reduction of voltage on the arc column.…”

Section: Selected Functions Approximating the Static Current-voltage mentioning

confidence: 99%

The Mayr-Pentegov Model of Electric Arc with Selected Static Current-Voltage Characteristics

Sawicki¹

2020

eBIS

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The basic properties of the Mayr-Pentegov mathematical model of the electric arc were described. A set of generalized functions has been selected to approximate static voltage-current characteristics. On their basis, derivatives of the conductance function relative to the squared current, which are used to calculate the non-linear damping function, were determined. Families of static characteristics dependent on parameters of approximating functions are presented. As a result of the simulations of processes in the circuit with the electric arc model, the family obtained dynamic voltage-current characteristics. By using wide ranges of parameter changes, the usability of the developed model using various approximations of static characteristics was demonstrated.

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Section: Selected Functions Approximating the Static Current-voltage mentioning

confidence: 99%

The Mayr-Pentegov Model of Electric Arc with Selected Static Current-Voltage Characteristics

Sawicki¹

2020

eBIS

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“…The non-linear earth-fault resistance R F was modeled as a series circuit consisting of the arc resistance R arc [11][12][13][14] and the transition resistance R T . The arc model has been used with parameters [11,12]: ignition voltage U ig = 10 kV, voltage in the arc column in a conducting state U k = 1000 V, resistance in a conducting state R 1 = 0.1 , time constant  = 0.1 ms. The protection was tested both in the case of low-resistance and highresistance short-circuits located at various points of the network marked in Figure 3.…”

Section: Tests Of the Protectionmentioning

confidence: 99%

General earth fault protection for MV networks using wavelet decomposition and Bayesian criterion

Marciniak

2019

E3S Web Conf.

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For selective detection of earth faults in medium voltage networks, the general protection can be used, which unlike individual protections controls earth currents in all lines supplied from the substation. To detect high-resistance and arc faults, it is possible to use in such protections the details from wavelet decomposition of earth currents and the Bayesian conditional probability criterion. The paper presents a protection model using details of earth currents and the Bayesian criterion. Significant parameters of the model were determined: sampling frequency, wavelet types and decomposition levels, parameters of the probability density function and decision conditions. The effectiveness of the protection in the case of non-stationary high-resistance short-circuits in the network with natural asymmetry and harmonic distortion was also assessed.

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“…suited. The asymmetry reactive power for third harmonics is the smallest, and, as shown in [4][5][6], the non-linear resistance of the earth fault, especially an arc resistance [13][14][15][16], generates mainly the third harmonics of the zero sequence current and voltage. The protection using criterion Q 031 will have the lowest setting and the highest sensitivity.…”

Section: Research On the Impact Of The Capacitive Asymmetry On The Zementioning

confidence: 99%

The influence of the network asymmetry on the settings and sensitivity of an earth fault protection using higher harmonics

Marciniak

Piątek

2019

E3S Web Conf.

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Detection of high resistance earth faults in medium voltage networks is an important problem due to ineffectiveness of traditional earth fault protections. Such short circuits can be detected by the criterion of a reactive power of higher harmonics for zero sequence current and voltage. The main problem is determination of the power setting value in the protection, which depends on the asymmetry of phase-to-earth capacitances and higher harmonics in supply voltages, which are generated by non-linear loads. The intensive tests of the asymmetry of the zero sequence currents and voltages for harmonics and their reactive power have been carried out in 15 kV compensated network as a function of all relevant parameters, i.e.: maximum capacitance deviation of the network and protected line, percentage content of harmonics in supply voltages, capacitive current of the network and the line. It has been shown that third harmonics of the zero sequence voltage and current are the best suited for practical use, since the asymmetry reactive power of these components is the smallest among the considered harmonics and the protection sensitivity will be the highest.

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Model of the arc earth-fault for medium voltage networks

Cited by 15 publications

References 5 publications

The Mayr-Pentegov Model of Electric Arc with Selected Static Current-Voltage Characteristics

The Mayr-Pentegov Model of Electric Arc with Selected Static Current-Voltage Characteristics

General earth fault protection for MV networks using wavelet decomposition and Bayesian criterion

The influence of the network asymmetry on the settings and sensitivity of an earth fault protection using higher harmonics

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